Grey horizontal screen display issue when navigating Add Pending Worker?

We have had incidents in both Convert Pending Worker and Add Pending Worker whereby the screen view changes to a horisontal grey block view and stops users being able to complete the transaction. This was happening when users navigate back and forth on the redwood compact guided workflow (typically after the assignment or payroll sections). The issue is really sporadic which makes it hard to reproduce when going through the Oracle SR process. Has anyone else hit the same problem and have they managed to get reproducible cases/insight into why it happens.